The Zimmermann Brake Kit - Front/Rear - 138885 is a comprehensive kit of products designed to service the brakes of a car. It includes a variety of components for both the front and rear brakes, providing a complete solution for maintaining and improving the braking system of a vehicle. The kit contains four objects, each with a specific function in the brake system. These objects include brake pads, rotors, calipers, and brake sensors. The brake pads are responsible for creating friction against the rotors to slow down or stop the vehicle. The rotors are the discs that the brake pads press against, and the calipers are the housing that holds the brake pads and applies pressure to them. The brake sensors are electronic components that monitor the condition of the brake system and alert the driver if there are any issues. This kit is ideal for those looking to upgrade or replace their current brake system, as it includes all the necessary components for a complete and efficient brake service.